Hey! Your rational number would be 
Answer: 
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Reason:
Plot the points (0,0) and (r,s). You can place (r,s) anywhere you want.
Connect the two points mentioned and form a right triangle such that the segment from (0,0) to (r,s) is the hypotenuse of said right triangle.
The horizontal leg has a length of r-0 = r units, while the vertical leg will be 's' units.
Check out the diagram below.
We then apply the pythagorean theorem to say
where h is the hypotenuse. Solving for h gets us
. We only focus on the positive square root since a negative hypotenuse makes no sense.
Since we made the hypotenuse the segment with endpoints (r,s) and (0,0), this means the hypotenuse length and the distance are the same thing.
Therefore, the distance from (r,s) to (0,0) is 
As an alternative, you can use the distance formula to get the same answer. The distance formula is effectively the pythagorean theorem phrased a different way.
A quadratic equation has the general form
of: <span>
y=ax² + bx + c
It can be converted to the vertex form in order
to determine the vertex of the parabola. It has the standard form of:
y = a(x+h)² - k
This can be done by completing a square. The steps are as follows:
</span><span>y = 3x2 + 9x – 18
</span>y = 3(x2 <span>+ 3x) – 18
</span>y + 27/4= 3(x2 <span>+ 3x+ 9/4) – 18
</span>y = 3(x2 + 3/2)^2 – 99<span>/4
</span>
Therefore, the first step is to group terms with the variable x and factoring out the coefficient of x^2.